In a conventional relay, an operation indicator is provided, by which an operator makes a functional check on the relay. Such the operation indicator is provided in the vicinity of a ceiling of the relay (a top surface of a box), in general, in order to allow an operator to visually recognize a lighting situation more easily.
However, terminals used for supplying power to the relay (including the operation indicator) are usually located on a bottom surface of the relay. For this reason, there has been a need for laying a relatively long wire which extends from the terminals to the operation indicator placed in the vicinity of the ceiling of the relay.
On the other hand, in recent years, there is an increasing demand for scale-down of electronic components such as a relay. However, a smaller relay has a disadvantage that a space for an operation indicator cannot be saved in the vicinity of a ceiling thereof in some cases. In those cases, an operation indicator has no choice but to be placed apart from a ceiling. However, such location of the operation indicator causes a problem that an operator has difficulties in visually recognizing a lighting situation.